Turbine



Sept. 24, 1929. R. BIRMANN 1,728,921

TURBINE Filed ocx. 14, 1926 2 sheets-sheet 2 n f1 a Patented Sept. 24, 1929 UNITED STATES PATENT yOFFICE RUDOLPH BIRMANN, or TRENTON, NEW JERSEY, AssIeNoRy :To DE LAVAL STEAM TURBINE COMPANY, F TRENTON, NEW JERSEY, A, CORPORATION OF NEW JERSEY i TURBINE Application filed October 14, 1926*. Serial No. 141,493.

My invention relates to an improvement in steam turbines.

Turbines of the character to which my invention more particularly relateshave heretofore been constructed as what are generally known as the single stage wheel type or as velocity compounded wheel, or combinations of the two. f

Those turbines of the single stage wheel type have the advantage of high efficiency, but the serious disadvantage of low energy absorption, while in those turbines ot the velocity compounded wheel type the characteristics are reversed and they possess relatively low efficiency and high energy absorption.

Turbines have been constructed heretofore which possess both high efficiency and high energy absorption. Such turbines are usually provided with two or more single velocity pressure stages arranged in such a way that the leaving velocity of the working fluid, as it leaves the buckets of a stage is utilized as much as possible in the next following stage. This can only be accomplished by closely spacing the wheels and by keeping the arc of admission of the working fiuid traversing the wheels and diaphragme constant, and further, by so arranging the angles of the guide vanes that they will be in the exact direction ot the steam jet entering them.

Such turbines, while possessingA the dual ladvantage of high efficiency and high energy absorption, are open to certain objections, chief among which is that they do not lend themselves to the passage of a larger flow of working fluid through the stages than that for which the blading is designed.

Now, it is the object of my invention to provide a turbine se constructed as to possess both high efficiency and high energy absorption and at the same time, one in which an additional or auxiliary flow of working fluid, or more than one, may be utilized at will, in order that the turbine may be operated efficiently under various loads.

Having now indicated, in a general Way, the nature and purpose of my invention, I will proceed to a detailed description thereof with reference to the accompanying drawings, in which there is Villustrated a preferred embodiment and in which:

Fig. 1 is a partial end view, partly in section and partly broken away, of a .turbine embodying my invention.

Fig. 2 is a partial sectional view of the turbine shown in Fig. 1.

Fig. 3 is a sectional view on line 3, Fig. 2. Fig. 4 is a sectional view on line 4, Fig. 2. a indicates a casing on which is formed a main steam chest b connected through an inlet fiange Z2 to a source of steam supply. c and d respectively, indicate first and second stage wheels mounted on a shaft e each provided with buckets f, While g indicates a diaphragm positioned between the wheels c and d. The wheels are arranged in close proximity with a series of ports ornozzles, formed by guide vanes h, the angle of which is such as to place the inlets in line with the direction of the steam leaving the buckets f of the first stage wheel c so that the steam will pass into the nozzles with minimum loss of velocity. The guide vanes are so shaped as to cause an increase in the velocity of the steam delivered tothe buckets ofthe second stage wheel d. l

Within fthe steam chest b at the ends thereof, are formed auxiliary steam chests i provided with openings j, which aord a passage for the entry of steam from the main steam chest and which are controlled by valves 7c adapted to be manipulated through the medium of hand wheels mounted on the ends of the stems Z4 of the valves external of the casing.

Nozzles m, of desirable shape andhaving overhanging lips n, are provided, opposite to the nozzles in diaphragm g, for the passage of steam from the main steam chest to the buckets f of the first stage wheel c.

The diaphragm g opposite to the auxiliary nozzles m leading from the auxiliary steam` chests z' is blank but milled out on a curve, as indicated ato to catch Vsteam passing from the auxiliary steam chestsz' and through the buckets f of the first stage wheel, and guide it upwardly into a Vchamber p, which extends above the nozzles m. Steam from the chamber p passes to the second stage' nozzles,

formed by the vanes L, through narrow openings formed between the lips n on nozzles m and lips g, formed on the diaphragm g, eX- tending above lips n. rIlhe lips form passages for the steam from chamber 29 and also guide it so that it Will be discharged'between the vanes h in substantially the same direction as that discharged from the ybuckets f with which it mingles and passes to thesecond stage. y

It'will now be observed if, with the turbine in operation, the valves c are closed, there will be no live steam in the auxiliary chests z' and the first stage wheel-will receive live steam only from the nozzles m connecting with the main steam chest. p i

If now the load on the turbine be increased, oney or both of the valves ic' may be opened, depending upon the demands of the occasion, and steam from themain steam chest will enter eithery or both of the auxiliary chests z' and pass through nozzles m to the wheel c.

The steam leavingr the buckets fof wheel c, which are supplied with steam-from the nozzles m, will pass into the nozzles formed by vanes k' and hence to the second stage wheel d. Steam from the buckets of wheel c, which are supplied with steam from the nozzles m, however, will pass up into chamber p guided thereto by the curved face of the milled out portion 0 of diaphragm g. Chamber p will act more or less as an equalizing chamber and distribute the steam to the nozzles'formed by vanes L, to which the steam will pass through the narrow passage formed between lips aand q, in which its velocity will be increased and by which *it will be directed to join tlie steam discharged by the buckets f at a small angle thereto.

Having now fullydescribed my invention, what I claim anddesire to protect by Letters Patent is 1.,In a steam'turbine, in combination, a main steam chest, firstv and second stage wheels, a diaphragm between said wheels, nozzles affording a'passage for steam from the steam chest to the first stage wheel, passages formed in said diaphragm affording a passage for steam discharged from said first stage wheel to said second stage wheel, an auxiliary nozzle affording a passage for steam to said `first stage wheel, a conduit, a recess in communication with said conduit formed in said Idiaphragm opposite =to said auxiliary nozzle and adapted to lead steam from said auxiliary nozzle into' said conduit after it has passed through said first stage wheel, said conduit being provided with an outlet for the. discharge of steam therefrom into said passages in said diaphragm inea direction substantially the samevas that in which steam is discharged from said first stage wheel.

2. In asteam turbine, in combination, a

" main. steam chest, first and second sta-ge passage for steam discharged from said first stage wheel to said second stage wheel, an auxiliary steam chest formed within the main steam chest, means for controlling the admission of'steam to the auxiliary steam chest,

y an auxiliary nozzle4 affording a passagefor steam from the auxiliary steam chest to the first stage wheel, means for receiving steam from the auxiliary steam chest, after it has passed through the first stage wheel, and for discharging it into the passages in said diaphragm in a direction substantially the'same as that at which steam is directly discharged from said first stage wheel into said passages.

3. In a steam turbine, in combination, a main steam chest, first and second stage wheels, a diaphragm between said wheels, nozzles affording apassage for steam from the steam chest to the first stage wheel, passages formed in said diaphragm affording a passage for steam discharged from said first stage wheel to said second stage wheel, an

auxiliary steam chest formed within the main steam chest, means for controlling the admission of steam to the auxiliary steam chest,

an auxiliary nozzle affording a passage for steam from the auxiliary steam chest to ,the first stage wheel, a conduit extending above said first stage wheel, a recess in communication with said conduit formedin said diaphragm and adapted to guide steam from said auxiliary nozzle into said conduit after it hasvpassed through said first stage wheel.J- said conduit being provided with a passage for the discharge of steam into said passages in said diaphragm in a direction substantially the same as that in which steam is discharged from said first stage wheel.

4. In a steam turbine, first and second stage wheels, a diaphragm between said wheels nozzles forleading steam from a supn ply to the first stage wheel, passages formed in the diaphragm and arranged to lead steam discharged from the first stage wheel to the second stage wheel, an auxiliary.1 nozzle for leading steam to the first stage wheel, means for controlling the flow of steam from said auxiliary nozzle, and means for leading steam subsequent to its passage from the auxiliary nozzle through the first stage wheel into the said passages formed in the diaphragm to mix it with other steam discharged from the first stage wheel for pasL sage to said second stage wheel.

In testimony of which invention, I have hereunto set my hand, at Trenton, N. J., on this second day of Oct., 1926.

RUDOLPH BIRMANN.

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